API key authentication

---
title: API key authentication
description: Authenticate OpenAI-compatible and Anthropic-compatible Relyven requests without exposing the API key.
lastUpdated: 2026-07-29
---

## OpenAI-compatible clients

Send the Relyven key as a bearer token:

```http
Authorization: Bearer sk-...
```

The same header is used for Responses, Chat Completions, Models, image, video, and audio endpoints.

## Anthropic-compatible clients

Send the key with the Anthropic version header:

```http
x-api-key: sk-...
anthropic-version: 2023-06-01
```

Claude Code can read the key from `ANTHROPIC_AUTH_TOKEN`. See the [direct Claude Code setup](/en/integrations/claude-code/) for the complete environment configuration.

## Store the key safely

Treat API keys as passwords. Put them in environment variables or a secret manager. Do not commit keys, add them to screenshots, or paste them into shared prompts. Rotate a key after exposure and remove it before sending logs to support.

Use `GET https://api.relyven.com/v1/models` to verify the key and view its current model scope.

OpenAI-compatible clients

Send the Relyven key as a bearer token:

Authorization: Bearer sk-...

The same header is used for Responses, Chat Completions, Models, image, video, and audio endpoints.

Anthropic-compatible clients

Send the key with the Anthropic version header:

x-api-key: sk-...
anthropic-version: 2023-06-01

Claude Code can read the key from ANTHROPIC_AUTH_TOKEN. See the direct Claude Code setup for the complete environment configuration.

Store the key safely

Treat API keys as passwords. Put them in environment variables or a secret manager. Do not commit keys, add them to screenshots, or paste them into shared prompts. Rotate a key after exposure and remove it before sending logs to support.

Use GET https://api.relyven.com/v1/models to verify the key and view its current model scope.